Thermodynamics, Statistical Physics, and Quantum Mechanics

87

The center of mass (inertia) of the gas found with the same accuracy is

given by

As we have assumedthat the tankerslides onfrictionless rails,the center
of mass of the system will not move but the center of the tanker will move
by an amount such that

Substituting(S.4.4.7)into(S.4.4.8) and rearranging give

4.5 Magic Carpet (Moscow Phys-Tech)

First let us try to reproduce the line of reasoning the Baron was likely to
follow. He must have argued that in the z direction the average velocity of
a molecule ofmass is

If we consider that during the collision the molecules thermalize, then the
average velocities after reflection from the upper and lower surfacesbecome

THERMODYNAMICS AND STATISTICAL PHYSICS